Portable electronic apparatus having a removable hard disk drive including an externally operable lock member

ABSTRACT

A portable electronic apparatus includes a housing having a storing section which has an insertion opening opened to the outside the housing. A HDD pack is stored in the storing section and detachable through the insertion opening. A HDD holder is connected to the HDD pack and detachably fitted in the insertion opening. A pair of sliders are provided on the HDD holder and movable between an engaged position where the sliders are engaged engagement holes formed in the housing to hold the HDD holder in the insertion opening and a retreated position where the sliders are disengaged from the engagement holes to allow the HDD holder to come into and out of the insertion opening. A lock member is provided on the HDD holder and movable between a locking position where the sliders are locked in the engaged position and a releasing position where the sliders are allowed to move.

This is a continuation of Ser. No. 08/195,604, filed Feb. 14, 1994, now abandoned, which was a continuation of Ser. No. 07/960,590, filed Oct. 13, 1992, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a portable electronic apparatus such as personal computers of the lap-top type and, more particularly, an electronic apparatus provided with a detachable unit such as a hard disk drive (which will be hereinafter referred to as HDD) unit and a battery pack, which are detachably set in a housing of the apparatus.

2. Description of the Related Art

Recently, a plurality of portable electronic apparatuses such as personal computers of book-type and lap-top types are on the market. Some of them have come to have such an arrangement that allows a 2.5-inch HDD to be set in them as an external memory unit with high speed and large capacity. The HDD is housed in a rectangular metal case and put on the market as an HDD pack. When this HDD pack is set in and connected to the computer, the memory capacity of the computer can be increased to a great extent.

Conventionally, the housing of the computer comprises a storing portion for storing the HDD pack. The HDD pack can be fixed at a certain position in the housing by storing the HDD in the storing portion and fixing it by means of screws which are into the HDD pack through the bottom of the housing.

When the HDD pack is fixed to the housing by using screws, however, it must be removed from the housing by using a tool such as the driver. Thus, the removing and attaching operations should be performed by using a tool in the every time when the HDD pack is exchanged with a new one with a greater capacity, the HDD pack is to be detached from the computer housing to make the computer itself so light as to more easily carry it, and the media in it are to be used for other computers.

This makes it troublesome to set and detach the HDD pack in and from the computer housing and the setting and detaching of the HDD pack relative to the computer housing need time and labor. This trouble is caused in the case of other detachable parts such as a battery pack as well as in the case of the HDD pack.

SUMMARY OF THE INVENTION

The present invention is therefore intended to eliminate the above-mentioned drawbacks and its object is to provide an electronic apparatus wherein a detachable unit can be easily attached to and detached from the housing of the apparatus and can be securely held in the housing.

In order to achieve the object, an electronic apparatus according to the present invention comprises a housing having a storing section which includes an insertion opening opened outside the housing; a detachable unit stored in the storing section to be removable from the storing section through the insertion opening; and a holding mechanism for holding the detachable unit in the storing section, said holding mechanism including an engagement portion provided on one of the housing and the detachable unit, an engaging member provided on the other of the housing and the detachable unit and movable between a engaged position where the engaging member engages the engagement portion to hold the detachable unit in the storing section and a retreated position where the engaging member is disengaged from the engagement portion to allow the detachable unit to come into and out of the storing section, and a lock member provided on the other of the housing and the detachable unit and movable between a locking position where the lock member locks the engaging member in the engaged position and a release position where the lock member allows the engaging member to be moved.

According to the electronic apparatus arranged as described above, when the engaging member is moved to the engaged position to engage with the engagement pottion while the detachable unit is set in the storing section, the detachable unit is connected to the housing and held in the storing section when the lock member is then moved to its locking position, the engaging member can be locked in its engaged position, thereby keeping the engagement between the engaging member and the engagement portion. The detachable unit can be thus held in the storing section of the housing with higher reliability.

When the detachable unit is to be detached from the storing section, the above process is reversely conducted. In short, after moving the lock member the release position, the engaging member is moved to the retreated position. Thus, the engaging member is disengaged from the engagement portion, thereby allowing the detachable unit to be detached from the storing section through the insertion opening.

According to the electronic apparatus having the above-mentioned arrangement, the detachable unit can be fixed in the storing section of the housing without using any screw. Therefore, the setting and detaching of the detachable unit in and from the storing section of the housing can be achieved without using any tool such as the driver. Further, the engaging member can be locked by the lock member while keeping the detachable unit set in the storing section. The detachable unit can be thus held in the storing section with higher reliability and it cannot happen that the detachable unit wrongly comes out of the storing section.

Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate a presently preferred embodiment of the invention, and together with the general description given above and the detailed description of the preferred embodiment given below, serve to explain the principles of the invention.

FIGS. 1 through 12 show a personal computer according to an embodiment of the present invention, in which

FIG. 1 is a perspective view showing the computer;

FIG. 2 is a perspective view showing the structure of a battery pack and a battery pack storing section;

FIG. 3 is a perspective view showing a part of the computer housing together with a hard disk drive pack and a memory card which are to be set in the computer housing;

FIG. 4 is a sectional view showing a part of a function label and a holder groove enlarged;

FIG. 5 is a sectional view of a HDD holder taken along a line V--V in FIG. 3;

FIG. 6 is an exploded perspective view showing the HDD holder;

FIG. 7 is a front view showing the HDD holder in a state wherein a slider is moved to its retreated position and a rear cover is removed;

FIG. 8 is a front view showing the HDD holder in a state wherein the slider is moved to its latched position and the rear cover is removed;

FIG. 9 is an exploded perspective view showing a part of the personal computer, including a memory card storing section and an ejecting plate;

FIG. 10 is a perspective view showing the memory card storing section with a memory card inserted, but an upper case is removed;

FIG. 11 is a sectional view taken along a line XI--XI in FIG. 9; and

FIG. 12 is a sectional view taken along a line XII--XII in FIG. 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, a lap-top type personal computer according to an embodiment of the present invention includes a flat rectangular housing 10 which comprises a combination of upper and lower cases 10a and 10b both made of synthetic resin. A rear end portion of the upper surface of the upper case 10b projects upward and constitutes a projected portion 10c which extends in the width direction of the housing 10. The projected portion 10c has a pair of recesses 12 separated from each other in the width direction of the housing 10. A keyboard 16 having a plurality of keys 14 is attached to the upper case 10a and the keys 14 are exposed outside through an opening which is formed at the front top portion of the upper case 10b.

A display unit 18 of the flat type is rotatably mounted on the housing 10. The display unit 18 is shaped like a rectangle and a pair of legs 20 serving as pivotal portions project from the lower end of the display unit 18. These legs 20 are positioned in the recesses 12 of the projected portion 10c and rotatably attached to the housing 10 by means of hinges (not shown). The display unit 18 therefore is rotatable between an opened position where the keyboard 16 is exposed to enable the computer to be operated, as shown in FIG. 1, and a closed position where the keyboard 16 is covered by the display unit. When the display unit 18 is closed, its top face becomes flush with the top face of the projected portion 10c. Latch claws 19 are provided at upper right and left end portions of the display unit 18. These latch claws 19 are engaged with latch holes 21 on the front top of the upper case 10b to lock the display unit 18 in the closed position.

As shown in FIGS. 1 and 2, the housing 10 has a battery pack storing portion 22 formed of a rectangular recess 22 which is open to the top face of the upper case 10b between the keyboard 16 and the projected portion 10c. The storing section 22 extends from the left side to the center of the housing 10. A battery pack 24 is detachably fitted in the storing section 22.

The battery pack 24 is shaped like a rectangular box having same dimension as that of the battery pack storing section 22. A pair of projections 25 project from the right side of the battery pack 24 and fitted into engaging holes (not shown) of the upper case 10b. Terminals (not shown) are arranged on the left side of the battery pack 24 to contact receiving terminals 26 which are provided on the left side of the battery pack storing section 22. When the battery pack 24 is set in the storing section 22, its top face is flush with that of the upper case 10b to form a part of the top of the housing 10. It can be held in the battery pack storing section 22 by a lock mechanism (not shown).

As described above, the battery pack 24 is located between the keyboard 16 and the supports or legs 20 of the display unit 18. When the display unit 18 is opened, therefore, setting and releasing of the battery pack 24 into and from the battery pack storing section 22 of the housing 10 cannot be disturbed by the display unit 18, thereby enabling the battery pack 24 to be easily set into and detached from the storing section 22 at the front side of the housing 10. In addition, the legs 20 of the display unit 18 can be arranged on the rear end of the housing 10, so that the size of the display unit 18 can be made as large as the housing 10.

When the display unit 18 is rotated to its closed position, the battery pack 24 is covered by the display unit 18. Even when the lock mechanism for the battery pack 24 is wrongly unlocked during the computer is carried with the display unit 18 being closed, therefore, the battery pack 24 can be prevented from being removed from the housing 10.

A function label 26 for showing functions of function keys of the keyboard 16 is mounted, adjacent to the keyboard 16, on the top face of the upper case 10b. It is made of synthetic resin and shaped like a strip extending along the whole length of the housing 10 in the width direction thereof.

The function label 26 is fitted in a holding groove 28 which is formed on the top face of the upper case 10b and has the same shape and dimension as those of the function label 26. The holding groove 28 extends onto the battery pack 24. Specifically, the groove 28 is comprised of a right half (or first portion) 28a formed on the top face of the upper case 10b and a left half (or second portion) 28b formed on the top face of the battery pack 24. When the battery pack 24 is fitted in the battery pack storing section 22, therefore, the left half 28b is combined with the right one 28a to form the holding groove 28. The function label 26 is held in the holding groove 28 by a pair of first holding claws 30a projecting from the top face of the upper case 10b toward the right half 28a of the holding groove 28 and by a pair of second holding claws 30b projecting from the top face of the battery pack 24 toward the left half 28b thereof.

When the battery pack 24 is in the battery pack storing section 22 of the housing 10, the left half of the function label 26 is on the battery pack 24, as shown in FIG. 1. When the battery pack 24 is to be detached from the pack storing section 22, therefore, the function label 26 disturbs this detaching of the battery pack 24. In order to overcome this, a right end edge 28c of the holding groove 28 which is in opposite to the battery pack 24 is tilted relative to the bottom of the holding groove 28, as shown in FIG. 4. When the battery pack 24 is to be fitted into and detached from the pack storing section 22, therefore, the function label 26 can be easily pulled out of the holding groove 28 from the right end 28c thereof and retreated from the battery pack 24, as shown by a two-dot and dash line in FIG. 2. The battery pack 24 can be therefore fitted into and detached from the pack storing section 22 without being disturbed by the function label 26.

As shown in FIG. 3, in the housing 10 is formed a storing section 34 for storing a hard disk drive (which will be hereinafter referred to as HDD) pack 32, which has a box-shaped case 32, and a HDD holder 36. The storing section 34 is arranged side by side with the battery pack storing section 22 and provided with an insertion opening 34a at the right rear side of the housing 10. As shown in FIGS. 1 and 2, the opening 34a of the storing section 34 is usually closed by the HDD holder 36. These HDD pack and holder 32 and 36 constitute a detachable unit of the present invention.

As shown in FIGS. 3 and 5 through 7, the HDD holder 36 includes a plate-like holder body 38 having the same shape as that of the opening 34a of the storing section 34, and a rear cover 40 fixed to the rear side of the holder body 38 and having substantially the same dimension as that of the holder body 38. The rear cover 40 has a pair of parallel holder arms 42 extending backwards and perpendicular to the holder body 38 from both ends of the rear cover 40. These paired holder arms 42 are spaced apart from each other by a distance substantially equal to the width of the case 31 of the HDD pack 32. Each of the holder arms 42 has a slit 42a extending in the longitudinal direction of the arm 42.

The rear cover 40 includes a pair of through-holes 43 at upper both ends thereof, a pair of engagement holes 44 at the top thereof, and plural projections 45 at the bottom thereof. On the other hand, the holder body 38 includes a pair of threaded bosses 46, a pair of projections 47 corresponding to the engagement holes 44 of the rear cover 40, and plural engagement holes 48 corresponding to the projections 45 of the rear cover 40. The rear cover 40 is therefore fixed to the holder body 38 in such a way that screws 49 are screwed into bosses 46 of the holder body 38 through the through holes 43 while engaging the projections 45 with the engagement holes 48 of the holder body 38 and the projections 47 of the holder body 38 with the engagement holes 44.

A pair of sliders 50 and a lock member or plate 52 are slidably arranged between the holder body 38 and the rear cover 40. Each of the sliders 50 is slidably guided in the longitudinal direction of the holder body 38 or in a direction parallel to the top face of the upper case 10b by a guide rib 54 on the rear side of the holder body 38. A latch claw 56 made of metal is fixed to each of the sliders 50. Each slider 50 can slide between a retreated position where its latch claw 56 is retreated between the holder body 38 and the rear cover 40, as shown in FIG. 7, and a latched position (or engaged position) where its latch claw 56 projects from the side rim of the holder body 38, as shown in FIG. 8. The sliders 50 and their latch claws 56 serve as engaging members of the present invention.

A guide groove 58 is formed on the front side of the holder body 38, extending in the longitudinal direction of the body 38. A pair of operation knobs 60 are slidably fitted in the guide groove 58. Each of the operation knobs 60 includes an engaging claw 61 projecting backwards passing through an opening 62 of the holder body 38 and engaged with an engagement hole 63 of the corresponding slider 50. The operation knobs 60 are thus connected to their corresponding sliders 50 and can slide together with them. By sliding the operation knobs 60, therefore, it is possible to slide the sliders 50 from the front side of the holder body 38.

The lock plate 52 serving as a lock member of the present invention is arranged between the paired sliders 50 and guided by the guide ribs 54 to be slidable between a releasing position shown in FIG. 7 and a locking position shown in FIG. 8 in a direction perpendicular to the direction in which the sliders 50 slide. The lock plate 52 has a pair of projections 52a projecting from its bottom end in directions opposite to each other and it is therefore shaped like a fallen T. The lock plate 52 also has an engaging projection 71 projecting upwards from its top. When the lock plate 52 is in its releasing position, the projections 52a are positioned lower than inner ends of the sliders 50 and shifted from them to allow the sliders 50 to freely slide. When the sliders 50 are moved to the latched positions and the lock plate 52 is moved to the locking position, the projections 52a comes between the inner ends of the paired sliders 50 and prevent the sliders 50 from moving to the retreated positions. Projections 52a are thus abutting portions of the locking member, and the inner ends of the sliders 50 are receiving portions which are engaged by the abutting portions to restrict the movement of the engaging member. The sliders can be thus locked at their latched positions. These sliders 50 and the lock plate 52 form a holding mechanism for holding the detachable unit in the storing section 34.

As shown in FIGS. 3 and 5, an operation projection 65 protrudes from the front side of the lock plate 52. The operation projection 65 projects outside the holder body 38, passing through an opening 66 of the body 38. The lock plate 52 can thus slide between its releasing and locking positions by the operation projection 65 on the front side of the holder body 38.

As shown in FIGS. 5 and 6, an engaging projection 67 projects from the rear side of the lock plate 52. The rear cover 40 has an elastic cantilevered piece 68 which is formed by cutting a part of the rear cover 40 and which is opposed to the lock plate 52. A protrusion 69 projects from a free end of the elastic cantilevered piece 68 toward the lock plate 52 when the lock plate 52 is moved from its releasing position to its locking position, the engaging projection 67 abuts against the projection 69 of the piece 68 to elastically deform the piece 68 in a direction in which the piece 68 is separated from the lock plate 52. When the lock plate 52 comes to its locking position, causing its projection 67 to slide upward over the protrusion 69 of the piece 68, the cantilevered piece 68 returns to its initial position due to its elasticity. The protrusion 69 is thus struck against the bottom rim of the engaging projection 67, so that the lock plate 52 can be elastically held in its locking position shown in FIG. 5. When the lock plate 52 is in its releasing position, the protrusion 69 is struck against the top rim of the projection 67 to elastically hold the lock plate 52 in its releasing position.

when the HDD pack 32 is to be set in the storing section 34 of the housing 19, as shown in FIG. 3, the HDD holder 36 is attached to the HDD pack 32, holding one end portion of the HDD pack 32 between the holder arms 42 thereof. Engaging projections 32a (only one of them is shown in FIG. 3) projecting from both sides of this end portion of the HDD pack 32 are engaged with their corresponding slits 42a of the holder arms. In this state, the paired sliders 50 of the HDD holder 36 are set in their retreated positions and the lock plate 52 is in its releasing position.

The other end portion of the HDD pack 32 is then inserted into the storing section 34 through the insertion opening 34a and the HDD holder 36 is pushed together with the HDD pack 32 into the opening 34a. When the holder body 38 of the HDD holder 36 is fitted in the opening 34a, the paired sliders 50 are slid to their latched positions by the operation knobs 60. The latch claws 56 thus project from the side rims of the holder body 38 and fitted into and engagement portion which includes latched holes 70 of the housing 10. The latched holes 70 serve as engagement portions of the present invention. The lock plate 52 is then moved to its locking position by the operation projection 65 so that the paired sliders 50 are locked in their latched positions. When the lock plate 52 is moved to its locking position, the engaging projection 71 of the lock plate 52 is engaged with an engaging hole 73 formed in a partition wall 72 of the housing 10 which will be described later.

The HDD holder 36 is thus attached to the housing 10, keeping the opening 34a of the storing section 34 closed by the holder body 38. The HDD pack 32 is set at a certain position in the storing section 34. The holder body 38 forms, under this state, a part of the side wall of the housing 10 and it is exposed outside, as shown in FIGS. 1 and 2.

When the HDD pack 32 is to be detached from the housing 10, the above-described processes are reversely conducted.

When the HDD holder 36 arranged as described above is kept attached to the housing 10, its holder body 38 forms a part of the side face of the housing 10. This makes it unnecessary to use a cover for covering the front side of the holder body 38, thereby enabling the number of parts used to be reduced and the housing 10 to be smaller-sized. When the operation knobs 60 are exposed outside together with the holder body 38, there is fear that they are wrongly pushed. However, the paired sliders 50 are locked in their latched positions by the lock plate 52. Their moving can be therefore prevented even when the operation knobs 61 are wrongly pushed. Thus, the detachable unit including the HDD pack and holder 32 and 36 can be stably set in the storing section 34 without undesirably getting out of the housing 10.

As shown in FIGS. 3, 9 and 10, a storing section 76 for storing a card-like electronic member such as a memory card 74 is formed between the partition wall 72 of the housing 10, which forms the top of the HDD pack storing section 34, and the top wall of the upper case 10b. The memory card storing section 76 includes an insertion opening 76a opened at the top and the side faces of the housing 10. This insertion opening 76a is positioned on the opening 34a of the HDD pack storing section 34 and usually closed by a cover 77.

A pair of guide ribs 78 are formed on the top face of the partition wall 72, extending from the insertion opening 76a into the housing 10. They are opposed to each other and separated from each other by a distance substantially equal to the width of the memory card 74. A connector 80 to which terminals (not shown) of the memory card 74 are connected is fixed on the top face of the partition wall 72. This connector 80 is positioned at the inner end portion of the storing section 76.

As shown in FIGS. 9 through 12, an ejecting plate 82 for ejecting the memory card 74 out of the storing section 76 is attached to the underside of the top wall of the upper case 10b and located above the storing section 76. Specifically, the ejecting plate 82 is slidably guided, by guide ribs 83 projecting from the underside of the top wall of the upper case 10b, in a direction parallel to the card inserting and ejecting direction. It is also held on the underside of top wall of the upper case 10b by a holding plate 84, which is attached to the underside of the top wall of the upper case 10b, covering a part of the ejecting plate 82.

A metal plate 82a is attached to that inner end of the ejecting plate 82 which is opposed to the insertion opening 76a. The metal plate 82a has a pair of pressing claws 86 bent toward the partition wall 72 and these pressing claws 86 are separated from each other in the width direction of the memory card 74 and projecting into the storing section 76.

The ejecting plate 82 includes an operation knob 87 projecting toward the upper case 10b and positioned in an opening 88 of the upper case 10b. The ejecting plate 82 can be therefore operated from outside the housing 10 by the operation knob 87. When the memory card 74 is inserted into the storing section 76 through the insertion opening 76a by a certain length, that end rim of the memory card 74 which is inserted into the storing section 76 abuts against the pressing claws 86 of the ejecting plate 82. When the memory card 74 is further inserted into the storing section 76 until its terminals are connected to the connector 80, the ejecting plate 82 is also slid together with the memory card 74. The pressing claws 86 are then received into their corresponding recesses 90 of the connector 80.

when the memory card 74 is to be ejected from the storing section 76, the ejecting plate 82 is slid toward the insertion opening 76a through the operation knob 87. The inner end rim of the memory card 74 is thus caught by the pressing claws 86 of the ejecting plate 82 and the memory card 74 is pushed out through the insertion opening 76a, associating with ejecting plate 82. When the memory card 74 is pushed out through the opening 76a by a certain length, it is pulled out of the storing section 76 by the operator.

As described above, the ejecting plate 82 is flat and it is positioned close to the underside of the upper case 10b. In addition, it has a dimension smaller than the plane one of the storing section 76. Further, the ejecting plate 82 is arranged in the storing section and it is allowed to move in the storing section 76. Still further, the ejecting plate 82 can be directly operated from outside the housing 10 by the operation knob 87 and this makes it unnecessary to use a link mechanism and another operation button attached to the side wall of the housing. The ejection mechanism realized by this ejecting plate can be made more compact and simpler in structure to occupy a smaller space.

The present invention is not limited to the personal computers but it may be applied to other electronic apparatus such as the word processor. The card-like electronic parts cannot be limited to the memory card but it may be a modem card.

Although the detachable unit has included the HDD pack and the HDD holder detachably attached to the HDD pack in the above-described embodiment, the HDD holder may be omitted. In this case, the sliders (or engaging members) and the lock plate which constitute the holding mechanism will be attached directly to the case of the HDD pack. Further, the detachable unit is not limited to a combination of the HDD pack and holder, but a battery pack may be used.

Still further, the holding mechanism may be formed by single engaging member and a single lock member. Moreover, it may be arranged that an engaging member and a lock member of the holding mechanism are provided on the housing of the computer and that an engagement portion (or latch holes 70) for engaging with the engaging members is formed at the detachable unit.

It should be understood that other various changes and modifications can be made without departing from the spirit and scope of the present invention. 

What is claimed is:
 1. An electronic apparatus comprising: a housing having an outer surface;a storing section formed in the housing and having an insertion opening opened to the outer surface of the housing; a detachable unit stored in the storing section and removable from the storing section through the insertion opening; and a holder detachably connected to one end portion of the detachable unit and detachably fitted in the housing to close the insertion opening of the storing section; said holder including a holder body having a face which forms a part of the outer surface of the housing; an engaging member provided on the holder body and movable between an engaged position where the engaging member is engaged by an engagement portion formed on the housing to hold the holder body in the insertion opening of the storing section and a retreated position where the engaging member is disengaged from the engagement portion to allow the holder body to come into and out of the insertion opening of the storing section; an operation member arranged on the face of the holder body and connected to the engaging member to move together with the engaging member; and a lock member provided on the holder body and movable between a locking position where the engaging member is locked in the engaged position and a release position where the engaging member is allowed to move, the lock member having an operating portion exposed to the outside of the face of the holder body.
 2. An electronic apparatus according to claim 1, wherein said engaging member includes a pair of sliders movable between the engaged and retreated positions, and said lock member is attached to the holder body so as to position between the pair of sliders in the engaged position when the lock is in the locking position and to retreat from between the pair of sliders when the lock member is in the release position.
 3. An apparatus according to claim 1, wherein said detachable unit includes a hard disk drive pack.
 4. An electronic apparatus comprising:a housing having an outer surface; a storing section formed in the housing and having an insertion opening opened to the outer surface of the housing; a detachable unit stored in the storing section and removable from the storing section through the insertion opening; and a holder for holding the detachable unit in the storing section; said holder including a holder body detachably fitted to one end portion of the unit and detachably fitted in the housing to close the insertion opening, the holder body having a face which forms a part of the outer surface of the housing when the holder body closes the insertion opening, an engaging member provided on the holder body and operable from the outside of the housing, the engaging member being movable between an engaged position where the engaging member engages with an engagement portion formed on the housing to hold the holder body in the insertion opening and a retreated position where the engaging member is disengaged from the engagement portion to allow the holder body to come into and out of the insertion opening of the storing section, and a lock member provided on the holder body and operable from the outside of the housing, the lock member being movable between a locking position where the engaging member is locked in the engaged position and a release position where the engaging member is allowed to move.
 5. An electronic apparatus according to claim 4, wherein said holder includes a pair of arms which extend from the holder body and detachably engage the detachable unit so that said one end portion of the detachable unit is held between the arms.
 6. An electronic apparatus comprising:a main body including an outer surface, an engaging portion, a storing portion provided within the main body and an insertion opening communicating with the storing portion and provided on the outer surface; and a detachable unit detachably stored in the storing portion through the insertion opening, the detachable unit including an engaging member being slidable between an engaging position wherein the engaging member engages the engaging portion to hold the detachable unit in the storing member and a disengaging position wherein the engaging member is disengaged from the engaging portion, and a locking member being slidable between a locking position wherein the locking member locks the engaging member in the engaging position and a releasing position wherein the locking member releases from the locking position and permits sliding movement of the engaging member.
 7. An electronic apparatus according to claim 6, wherein the engaging member includes a receiving portion, and the locking member includes an abutting portion for engaging the receiving portion of the engaging member in the locking position to restrict the movement of the engaging member.
 8. An electronic apparatus according to claim 6, wherein the detachable unit includes a hard disk drive pack.
 9. An electronic apparatus according to claim 6, wherein the detachable unit includes a detachable pack, and a holder unit for holding the detachable pack in the storing portion,the holder unit including; a holder body having a pair of arms detachably connected to one end portion of the detachable pack; and a face body attached to the holder body, for fitting in the insertion opening to close it, the engaging member and the locking member being slidably supported by the face body and being operable from the outside of the main body.
 10. An electronic apparatus according to claim 9, wherein the detachable pack includes a hard disk drive pack.
 11. An electronic apparatus comprising:a body including an outer surface, a storing portion provided within the body and an insertion opening communicating with the storing portion; a detachable unit detachably stored in the storing portion; locking means for holding the detachable unit in the storing portion, the locking means including an engaging portion which is provided at one of the body and the detachable unit, an engaging member which is provided at the other of the body and the detachable unit and is slidable between a first position wherein the engaging member engages the engaging portion to hold the detachable unit in the storing portion and a second position wherein the engaging member is disengaged from the engaging portion, and a locking member on one of the detachable unit and the body and positioned for contact with the engaging member, the locking member slidable between a third position wherein the engaging member is locked in the first position and a fourth position wherein the engaging member is allowed to slide.
 12. An electronic apparatus according to claim 11, wherein the locking member is provided in the detachable unit.
 13. An electronic apparatus according to claim 12, wherein the engaging portion is provided in the body, and the engaging member is provided in the detachable unit.
 14. An electronic apparatus according to claim 13, wherein the engaging member and the locking member are operable from the outside of the body.
 15. An electronic apparatus according to claim 14, wherein the detachable unit includes a hard disk drive pack.
 16. An electronic apparatus, comprising:a body; a detachable unit detachably provided within the body; and a holding mechanism for holding the detachable unit in the body, the holding mechanism including a first member slidable between a holding position wherein the detachable unit is held in the body and a first releasing position wherein the detachable unit is allowed to detach from the body, and a second member slidable between a locking position wherein the first member is locked in the holding position and a second releasing position wherein the first member is allowed to slide between the holding position and the first releasing position.
 17. An electronic apparatus according to claim 16, wherein the body includes an outer surface, and the first and second members are arranged to be slidable in a plane substantially in parallel to the outer surface.
 18. An electronic apparatus according to claim 17, wherein the holding mechanism includes a closing member detachably fitted to the body and having a face exposed to the outside of the body, and the first and second members are slidably provided on the face of the closing member.
 19. An electronic apparatus according to claim 18, wherein the detachable unit includes a hard disk drive pack.
 20. An electronic apparatus according to claim 16, wherein the first member includes a receiving portion, and the second member includes an engaging portion for engaging the receiving portion of the first member, when the first member locates in the holding position and the second member locates in the locking position.
 21. An electronic apparatus according to claim 20, wherein the detachable unit includes a hard disk drive pack.
 22. A method of locking a detachable unit within an electronic apparatus, comprising the steps of:storing the detachable unit in a storing portion provided within the electronic apparatus; sliding a first sliding member, provided on the detachable unit, into an engaging position wherein the first sliding member engages the electronic apparatus to hold the detachable unit in the storing portion; and sliding a second sliding member, provided on the detachable unit, into a locking position wherein the second sliding member engages the first sliding member to lock the first sliding member in the engaging position.
 23. A method according to claim 22, wherein the storing step includes detachably fitting a holder unit of the detachable unit to a detachable pack of the detachable unit, and inserting the detachable pack along with the holder unit into the storing portion.
 24. A method according to claim 23, wherein the first sliding member is provided on the holder unit, and the step of sliding the first sliding member includes a process of sliding the first sliding member into the engaging position to hold the holder unit in the storing portion. 